The energy utilities companies had carried out the traditional reading and elaboration of invoices to collect the supplying services after these services had been used by the consumer-client. Recently, there had been proposed state of the art prepayment systems techniques for the supply of public services for example: light, water or gas, like a form of overcoming some of the inconveniences of the traditional collection systems.
A sort of prepayment system was designed of such form that the purchase of the supply of electricity (water or gas) is done directly from a central station and the information regarding the bought amount then is communicated to the client's site where this supply is consumed. In the consumption point (local, establishment, home, etc.) of the client, a measuring device is installed and it receives the information of the prepayment communication and it also confirms the bought amount to the central station. Typically, the electricity measuring device is installed in the exterior of the business or home and a terminal that reads the prepayment information is placed along with the meter or is connected by means of a cable or by the electric supply cables to the meter, which is instead located in the inside. A disadvantage with these type of prepayment systems is that are difficult to install and expensive. Another problem with this typical prepayment system is that it doesn't provide two-way communication about the consumption information, of how the credit is used, where or which meter is using the credit, and information about tampering done to the meter.
Another sort of well-known prepayment systems is also based on the purchase of the electricity supply directly from a sales point previously determined, being the information of the supply bought amount stored in a magnetic card or in contact intelligent cards. This particular prepayment system requires the use of an electronic meter that includes a card reading device or a magnetic key and a series of additional control devices to manage the supplying of the electric energy.
Examples of the type of prepayment system above mentioned are disclosed in The U.S. Pat. No. 4,240,030 titled “Intelligent Electric Utility meter” granted to Jess R. Baterman and collaborators on Dec. 16, 1960, which describes an intelligent meter that uses an insertable magnetic card to regulate the energy supply. The U.S. Pat. No. 4,629,874 titled “Prepayment metering system” granted on Dec. 16, 1980, describes a system that uses an intelligent card and additional elements to determine the credit to regulate the supply of energy. The U.S. Pat. No. 4,731,575 “Prepayment metering system using encoded purchase cards” granted on Mar. 15, 1988 to Joseph W. Sloan, discloses a system that uses coded magnetic ribbon cards to transfer the purchase information from the collection office to the consumer. The U.S. Pat. No. 4,795,892 “Pre-paid commodity system” issued on Jan. 3, 1989, given to CIC Systems, Inc., consists of a system that uses a prepayment activated by a selling card for the supply of electricity, water, gas, etc. The U.S. Pat. No. 4,803,632 titled “Intelligent utility system” granted to Utility Systems Corp., issued on Feb. 7, 1989, describes a type of an external data processor meter that has a screen that uses reader equipment to accede and recover information, and a card payment reader device included in the LCD located inside the property. The U.S. Pat. No. 4,908,769 titled “Commodity metering systems” granted to Schlumberger Electronics (UK) Ltd., on Mar. 13, 1990, discloses a measurement system by prepayment that includes an electronic key and a slot to receive this electronic key. The U.S. Pat. No. 5,146,047 titled “Prepayment metering system using encoded purchase cards from multiple locations” granted to CIC Systems, Inc., on Sep. 8, 1992, is related with a prepayment system to supply public services using magnetic ribbon cards. The U.S. Pat. No. 5,668,538 titled “Modular electricity meter arrangement having remotely controllable switch” granted to Siemens Measurements Ltd., on Sep. 16, 1997, describes a meter disposition that includes a prepayment module that has a slot to insert intelligent cards, memory cards, etc. The U.S. Pat. No. 6,529,883 titled “Prepayment energy metering system with two-way smart card communications” granted to David M. Yee and collaborators on Mar. 4, 2003, describes a prepayment energy measurement system that uses an intelligent card to provide two way data communication to send information of the client to the supplier of the service.
However, a disadvantage with this type of prepayment meters with magnetic card reader or contact intelligent card lies on while the reader is being exposed to receive the prepayment cards, it turns vulnerable to damages (intentionally or not intentionally) by the user or due to saline atmospheres or high relative humidity. Another problem arises when the card reader is connected by a cable to the meter, since this cable is also susceptible to suffer damages. As well when the reader is incorporated to the meter, the meter has to undergo to important physical changes increasing its volume and turning it vulnerable to damages by exposing part of it to the environment, independently of turning them incompatible to the market existent connectors as the connectors S or A type.
There is still another type of prepayment systems to control the supply of electric energy, are those that incorporate ways of shutting off the supply when the credit has been finished. An example of such system is disclosed in the U.S. Pat. No. 5,959,549 titled “Communal metering system” granted to Andreas J. Synesiou and collaborators, on Sep. 28, 1999, which describes a measuring system that supplies electricity previously paid to a plurality of clients, where the supply and the energy shut off is done in a remote way. A disadvantage of this type of prepayment systems for electric energy supply control is that they require equipments for transmission and reception of information (for example, MODEM) toward and from the power station, besides of being expensive. Another problem with this system is that doesn't provide information about meter tampering.
Keeping in mind the defects of the previous technique is a purpose of the present invention to provide a prepayment system to control efficiently the supply of electric energy in electronic meters installed in the client's site.
Another object of the present invention is to provide a prepayment measurement system of energy that uses a meter tightly closed and an intelligent contactless card.
Yet more, another object of the present invention is to provide an energy prepayment measurement system that incorporates an automatic device for energy supply shut off.
Is still another object of the present invention to provide an energy prepayment system for measurement that by means of the use of contactless intelligent card could provide information to the supplier about the consumption, how the credit is being used, where or what meter is using the credit, and information about illicit and tampering done the meter.
A further object of the present invention is to provide an electric energy supply prepayment method by means of a contactless card-reader system.